Sliding clasp fasteners



May 20, 1969 F, GUN ET AL 3,444,598

SLIDING CLASP FASTENERS Filed April 11, 1966 I INVENIOES y 969 F. GLINDMEYER ET AL 3 ,444,598

SLIDING CLASP FASTENERS Fild April 11, 1966 Sheet United States Patent 3,444,598 SLIDING CLASP FASTENERS Friedrich Glindmeyer, Stolberg, Rhineland, and Fritz Darandik, Hamburg, Germany, assignors to William Prym-Werke K.G., Stolberg, Rhineland, Germany Filed Apr. 11, 1966, Ser. No. 541,598

Claims priority, application Germany, Apr. 13, 1965,

P 25128; Dec. 7, 1965, P 38,288

Int. Cl. A44b 19/04; A41h 37/06 US. Cl. 24-205.16 7 Claims The invention relates to a sliding clasp fastener comprising a stringer suitable for attachment to knitted articles.

With sliding clasp fasteners comprising stringers made from strips of metal, tmouldede substance, leather or the like, it is known to provide the edges of the stringers remote from the rows of locking elements with holes suitable for sewing the stringers to articles or with lugs for welding them on. Stringers of this kind are not very flexible and therefore unsuitable for attachment to knitted garments.

It is also known to provide the longitudinal stringer edge remote from the row of locking elements with loops so that the stringer can be knitted onto knitted garments. During manufacture of the stringer by weaving, these loops are formed by the weft insofar as the weft is extended beyond the edge of the stringer proper at predetermined intervals along the stringer.

Known sliding clasp fasteners have the disadvantage that the stringer remains unattractively exposed after it has been attached to a knitted garment. Frequently the required colour or tone of the fastener is not available.

The present invention aims to avoid these disadvantages and to provide a stringer which permits inconspicuous attachment to knitted articles by stitching or knitting. The stringer of the fastener should be visible as little as possible so that even differently coloured stringers can be used.

According to the invention, the apertures for stitching or knitting the stringer to garments are located near the row of locking elements. After the stringer has been knitted or stitched to a garment, preferably in conformity with the stitch spacing in the garment, the edge of the garment may extend right up to the row of locking elements of the sliding clasp fastener and thereby render the stringer invisible. However, there is yet another advantage that is obtainable by means of the stringer according to the invention. It is now also possible to make the stringer narrower than hitherto without detrimentally affecting a secure attachment. This can result in considerable saving of material.

The apertures in the stringer may be in the form of wide holes, narrow slots or loosely woven stringer sections, the edges of the apertures being resiliently urged towards one another by the inherent transverse elasticity of the woven yarn bounding the apertures, or in the form of loops located near the row of locking elements.

It is advantageous to arrange the apertures in a plurality of rows that extend longitudinally of the stringer. Firstly, this makes it possible to attach the stringer by knitting or stitching simultaneously through more than just one row of apertures, thereby increasing the reliability of the attachment of the stringer. However, it is also possible to have a different aperture spacing from one row of apertures to the next. This has the advantage that a single type of stringer can be used for attachment to knitted articles having different stitch sizes and different yarn thicknesses. When attaching the stringer to the knitted article, a row of suitably spaced apertures is chosen according to the stitch spacing and yarn thickness in the knitted article. Since these rows of apertures are in the vicinity of the ice row of locking elements of the sliding clasp fastener, the stringer will be adequately covered by the knitted article even if the outermost row of apertures is used for attachment. Screening of the stringer is enhanced if the apertures in the outer rows are more widely spaced than the apertures in the inner rows because the outer rows usually serve for stitching or knitting on with thicker yarn. The larger diameter and stitch size with such thicker yarn permits the knitted article to extend closer to the locking elements and will thus cover the stringer more effectively than is the case with thinner yarn.

The apertures in the stringer may be provided in various ways each of which has its own particular advantage.

With woven stringers it is advisable to weave the apertures into the stringer during manufacture. Apertures of this kind have the advantage that they do not fray at their edges. Again there are various ways of providing woven-in apertures.

In one form of the invention, the apertures are formed by periodically reversed wefts in the weave adjacent the locking elements.

In another form of the invention, astringer section in the vicinity of the locking elements is provided with more widely spaced warps than elsewhere in the stringer, thereby producing one or more rows of apertures. In the simplest case, such stringer section is in the form of a ladder in which the sides are formed by two spaced warps and the rungs are formed by wefts bridging the gap between the warps. The manufacture of such an apertured stringer is particularly simple and economical. Since the ladder rungs are flexible rather than rigid, a needle will encounter an aperture at practically every position along this row of apertures during attachment of the stringer to a knitted article. It is therefore unnecessary to take the precaution of spacing the apertures i conformity with a particular spacing of needle strokes during attachment. If a plurality of closely juxtaposed rows of such apertures are provided rather than just one row, then the need for accurate alignment of the apertures transversely of the stringer is also dispensed with.

In yet another form of the invention, the apertures are woven into the stringer simply by providing a more loosely woven stringer section in the vicinity of the locking elements. This can be done by allowing the warps to float at least periodically along such stringer section. The apertures so made are normally covered by the floating warps but the latter are pushed aside during application of the attaching needle, thereby providing a passage for the needle through the stringer. Apart from the aforementioned advantages, this form of the invention additionally enables the apertures to be covered.

The apertures may also be formed by punched holes in the stringer. This permits a desired spacing of apertures to be provided subsequently, even after manufacture of the fastener.

Praying of the apertures punched into stringers of textile material can be avoided if the stringer is impregnated or covered with plastics materials. Another way of preventing fraying and tearing of the apertures at their edges is by welding the apertures under heat. This can be carried out by the punching tools if the stringer is made of thermoplastic material or at least subsequently coated or saturated with thermoplastic material.

Examples of the invention are illustrated in the accompanying diagrammatic drawings wherein:

FIG. 1 is a fragmentary plan view of a sliding clasp fastener in the closed condition;

FIG. 2 is a cross-section on the line 11-11 in FIG. 1;

FIG. 3 is a fragmentary enlarged plan of another embodiment of sliding clasp fastener;

FIG. 4 is a very much enlarged plan of a fastener with woven stringers having the apertures woven in, and

FIG. 5 is a very much enlarged plan of another form of fastener having woven-in apertures.

Referring to FIGS. 1 and 2, the sliding clasp fastener consists of the halves 11, 12 each comprising a stringer 15, 16 carrying rows of locking elements 13, 14 respectively. The locking elements are interengaged and in the present case are formed by the helical windings of a plastic wire which is sewn to the stringers 15, 16.

The stringers are woven from lateral fibres such as cotton. After weaving, they are saturated with a plastics material. In the vicinity of the locking elements 13, 14, the stringers 15, 16 are each provided with a row 17, 18 of apertures 19, 20 respectively. The apertures 19, 20 permit the passage of a needle during attachment of the stringer to knitted articles. It will be noted that these apertures are spaced closer to the inner ends of the locking elements (such inner ends being indicated in broken lines in FIG. 1) than to the free edges of the respective stringers. In the present case the ratio of the spacing of the aperture centres from the inner ends of the locking elements and the free edges of the stringers is about 5:8.

Each half 31, 32 of the sliding clasp fastener in FIG. 3 comprises a row of interengaging locking elements 33, 34. These locking elements are produced by the spacial meandering of a plastics Wire woven to the respective stringers 35, 36 of the fastener.

The threads of the woven stringers are of weldable synthetic material. Each stringer is provided with two rows 37, 38 and 39, 40, respectively of apertures 41, 42. The spacing of the apertures in the row 37, 39 differs from that in the rows 38, 40, the apertures 41 being more widely spaced than the apertures 42. If the fastener 30 is stitched or knitted to knitted articles having a comparatively small stitch spacing, the rows 38 and 40 are used for attaching the fastener whilst the rows 37 and 39 are used for attachment to articles having a large stitch spacing. In most cases knitted articles with large stitch spacings use a thicker yarn and for this reason the apertures 41 are larger than the apertures 42.

The apertures 41, 42 are punched into the stringers. The punching tools are heated so that the edges of the apertures are welded during punching and fraying or tearing at the edges of the apertures is thereby minirnised or prevented. The outer apertures 41 are preferably no further from the inner ends of the locking elements than in the case of FIG. 1. In the illustrated case, the ratio of the distance of the aperture centres from the inner ends of the locking elements and the free edge of the respective stringer is 1:8 for the inner rows 38, 40 and 2:7 for the outer rows 37, 39.

In the case of FIG. 4, the apertures can be even closer to the inner ends of the locking elements, namely, in the ratio of about 1:9. FIG. 4 shows one half of a sliding clasp fastener 50 comprising a woven stringer 51 and a row 52 of woven-in locking elements having coupling faces 54 formed by the helical windings of a plastics wire 53.

The stringer 51 consists of warps 54 and wefts 55 which are introduced by a shuttle. The plastics wire 43 is introduced by a different shuttle. The wire 53 is woven into warps 56 which are thinner than the warps 54.

Close to the row 52 of locking elements there is a row of apertures, two of which are visible in FIG. 4 at 57 and 58. By following the course of the weft 55 at the location of the apertures 57, 58, it will be seen that said apertures are formed by reason of the wefts 55 being turned back at some positions rather than extending across the whole width of the stringer 51. More particularly, some of the wefts 55 are reversed where indicated at 59 and '60 at a short spacing from the row '52 of locking elements, namely in the region of the stringer 51 in which the holes 57, 58 are desired. The position of the aperture width is indicated in FIG. 4 by the chaindotted line 61.

The stringer is constructed as follows. After the weft 55 has extended several times across the whole width of the stringer 51, the weft 55 is brought from the side of the locking elements only up to the line 61 and then reversed to return to the locking elements. Thereafter the weft again extends across the entire stringer width an uneven number of times depending on the desired spacing between the apertures 57 and 58. In the vicinity of the aperture 58 the weft 55 extends from the free edge of the stringer only up to the line 61 and is then reversed to return to the free edge. This is repeated throughout the length of the stringer.

For the purpose of clarity, the warps 54 are shown straight in FIG. 4 except the two warps bounding the apertures '57 and 58. For this reason the apertures appear as narrow holes. In reality more than just two warps will assume an inclination. Consequently, the apertures 57, 58 will have a marked width transversely as well as longitudinally of the stringer.

In FIG. 5, a stringer 71 is provided with a marginal bead 73 carrying individual metallic locking elements 72. In the vicinity of the locking elements, the stringer 71 is provided with a woven strip 74 in which the spacing between adjacent warps 75, 76 is larger than in other woven regions of the stringer. The gap between the warps 75, 76 is bridged by the weft 77. This produces a row of closely juxtaposed apertures 78. In addition, the two warps 75, 76 of the strip 74 are more loosely connected to the weft 77 than the other warps of the stringer 71.

As a result of the inherent transverse elasticity of the warps 75, 76 and some of the adjacent warps as well as of the weft 76 in the vicinity of the apertures 78, the latter will normally not be as wide as shown in the diagrammatic representation of FIG. 5; instead, they will more closely be juxtaposed. By a suitable choice of the spacing between the yarn and the loose weave in the vicinity of the apertures, the stringer will appear to be closed, the threads bounding the apertures being resiliently crowded towards one another. They will be lightly pressed apart when passing a needle therethrough so that the stringer can be conveniently knitted or stitched to a knitted article. After the needle has passed through, the edges of the apertures will close again as 'far as is possible so that the stringer will again appear to be closed after attachment of the fastener.

The invention is not restricted to the illustrated examples. The apertures in the stringer may be formed by floating warps so as to produce a loose weave. Also, more than one row of apertures may be provided in the stringer of FIGS. 4 and 5 and, if desired, the stringer need not even be woven; plastics stringers may be used in which case the apertures could be moulded, punched or drilled.

We claim:

1. A slide fastener comprising, in combination, a pair of stringers each adapted to be connected by a thread to the loops at the edge portion of a knitted fabric and each including a woven tape and a row of locking elements fastened to one edge portion of the tape, said woven tape being provided with a plurality of apertures adjacent said locking elements and arranged spaced in longitudinal direction of said stringer at distances from each other according to the stitch spacing and yarn thickness of the knitted fabric to be connected thereto, said apertures being formed by a weave that is looser in the area of the apertures than in the remaining portion of said tape.

2. A slide fastener as defined in claim 1, wherein each of said stringers is provided with at least two longitudinally extending rows of apertures.

3. A slide fastener as defined in claim 1, wherein said woven tape has warp threads and weft threads, some of said weft threads extend all the Way through the width of said tape and some of said Weft threads are reversed prior to reaching the respective longitudinal edge of said tape to form said apertures in the region of said reversed weft.

4. A slide fastener as defined in claim 1, wherein said woven tape has warp and weft threads, said warp threads being arranged in two groups spaced in transverse direction from each other a distance greater than the spacing of the warp threads in each group so that said tape has to one side of said locking elements a longitudinally extending portion free of warp threads and said apertures being defined by the warp threads located at opposite sides of said longitudinally extending portion and the weft thread portions passing therethrough.

5. A slide fastener as defined in claim 4, wherein said longitudinally extending portion free of warp threads is closer to said one longitudinal edge of said stringer than to the other longitudinal edge thereof.

6. A slide fastener as defined in claim 1, wherein said apertures are formed by a longitudinally extending tape portion adjacent said locking elements which is more loosely woven than the remainder of said woven tape.

7. A slide fastener as defined in claim 6, wherein said more loosely woven tape portion is formed by portions of at least some weft threads extending over at least two adjacent warp threads located adjacent said locking elements.

References Cited FOREIGN PATENTS Germany.

11/ 1962 Great Britain.

Italy.

BERNARD A. GELAK, Primary Examiner.

US. Cl. X.R. 

1. A SLIDE FASTENER COMPRISING, IN COMBINATION, A PAIR OF STRINGERS EACH ADAPTED TO BE CONNECTED BY A THREAD TO THE LOOPS AT THE EDGE PORTION OF A KNITTED FABRIC AND EACH INCLUDING A WOVEN TAPE AND A ROW OF LOCKING ELEMENTS FASTENED TO ONE EDGE PORTION OF THE TAPE, SAID WOVEN TAPE BEING PROVIDED WITH A PLURALITY OF APERTURES ADJACENT SAID LOCKING ELEMENTS AND ARRANGED SPACED IN LONGITUDINAL DIRECTION OF SAID STRINGER AT DISTANCES FROM EACH OTHER ACCORDING TO THE STITCH SPACING AND YARN THICKNESS OF THE KNITTED FABRIC TO BE CONNECTED THERETO, SAID APERTURES BEING FORMED BY A WEAVE THAT IS LOOSER IN THE AREA OF THE APERTURES THAN IN THE REMAINING PORTION OF SAID TAPE. 